1. Field of the Invention
The invention lies in the field of recovering silver from cuprous chloride.
2. Description of the Prior Art
In the recovery of copper from its ores, particularly sulfide ores, it is well known, as disclosed in U.S. Pat. Nos. 3,785,944, and 3,972,711, in order to avoid the disadvantages of recovering copper electrolytically, pyrometallurgically, and by other methods, to solubilize the copper in the ore as cuprous chloride in a leach followed by cooling the solution to crystallize out the cuprous chloride and recover copper from the cuprous chloride crystals. A major disadvantage of wet recovery like this technique, is that impurities like silver and iron are carried over during the crystallization into the cuprous chloride crystals and end up as impurities in the final copper product. Some of these impurities are deleterious to the properties of copper and reduce its sale value. While the latter may not be necessarily true of silver, the failure to recover the high priced silver so that it is not sold along with the copper at the price of copper, detracts from the economic feasibility of the overall process. Impurities, such as iron, can be removed from the recovered copper by fire refining in the presence of oxygen but this procedure results in the finished product containing oxygen which adversely affects its conductivity.
Accordingly, it is an object of this invention to provide an effective process for recovering silver and removing iron from cuprous chloride.
It is another object of this invention to provide an improvement in the process for recovering copper from its ores in which the copper is solubilized as cuprous chloride, the cuprous chloride crystallized out and the copper recovered from the cuprous chloride crystals, the improvement being a procedure for recovering silver from the cuprous chloride crystals before copper is recovered from them.